Air filters are generally known in the art and are employed in a variety of applications including heating and ventilation systems. A typical air filter is composed of a filtering material; often paper, a nonwoven material or foam, and a frame or housing that supports the filtering material. Conventional air filters are typically designed to remove particulate matter from the air.
In some applications, particularly those related to commercial and industrial operations, the ventilation ducts may be quite large. Typically, several air filters are used in a filter bank. These filters may be installed into individual cells of an array or frame for holding individual filters or may slide into a rack that is adapted to hold a row of air filters in a side-by-side arrangement. Thus, an array of air filters arranged adjacent to one another is typically employed as a filter bank.
In some applications, particularly where air filters are installed in individual cells of an array, each air filter may be mounted in the cell using a separate mounting gasket or seal to reduce or eliminate air bypass. These gaskets or seals are typically connected or attached to the frame or periphery of an individual cell in an array and are not replaced when each air filter is replaced. The replacement of an air filter in these cells is a labor intensive and time-consuming task, since each gasket or seal creates a tight fit around the filter, the air filter needs to be removed from each individual cell and replaced with a new air filter, ensuring each individual filter is appropriately seated in the gasket or seal, among other tasks.
In other applications, several air filters are installed by sliding the air filters into a track that is adapted to hold a row of air filters in a filter bank. Problems encountered during installation include, for example, difficulty in moving the air filters along the track, aligning the many air filters together, slight distortion of the filter frame during manufacture or during installation, distortions in the filter track, accumulated debris or dust in the filter track that can be scraped up as the air filter is moved along the track, and the like. This difficulty may increase with the larger air handling systems having multiple large rows of filters in a filter bank. As a result, the conventional side-by-side arrangement of air filters in a filter bank often results in a small gap or space between adjacent air filters which may permit a portion of air flow to avoid being filtered by the air filter bank prior to being circulated throughout a building.
Moreover, the conventional side-by-side arrangement of air filters in a filter bank often results in a small gap or space between adjacent filters. As a result, a portion of air flow may avoid being filtered by the filter bank, bypassing the air filters (known as air bypass), prior to being circulated throughout the building. This may result in detrimental effects of unfiltered air flowing through a ventilation system, including adverse effects on individuals. In addition to these effects on individuals, unfiltered air flow may also induce mechanical problems within the ventilation system itself, which may result in improper heating and cooling operations within a building structure. Dust particles may be deposited on the heating and cooling coils, clogging the coils and impeding proper operation of the ventilation system. Cleaning such coils is both time consuming and expensive.
One solution to the problem of air bypass is described in U.S. Pat. No. 6,916,352 to Sutton et al. and relates to the use of “I” shaped connectors to join adjacent filters in a filter bank. The connectors are used to join individual filters in side-by-side relationship as they are inserted into a track or opening in a filter bank. Sides of adjoining filter panels are inserted into the opposed channels of the “I”-shaped connectors. The “I”-shaped connector fills the gap between the sides of the adjacent filters to reduce air bypass between the sides of adjacent filters. The disadvantage with this design is the need for a separate, non-integral connector pieces that must be joined to each filter upon installation.
Because the connector piece is inserted separately from the air filter, such an air filter installation process would disadvantageously be more time-consuming and cumbersome than that of installing filters alone. There is also the risk that an installer may inadvertently drop a connector piece into the filter bank and be forced to extract and reposition it, prolonging the installation process. In addition, installation may be dependent upon having an adequate supply of both connector pieces and air filters on site, possibly requiring installers to transport an increased volume of materials and supplies to installation sites.
Another solution to the problem of air bypass is described in US 2007/0084167 A1, which teaches using connectors with overlapping flaps. While these connectors are described as reducing air bypass, the connectors require the overlapping of flaps which can cause problems associated with proper alignment and positioning of the air filters in the filter bank or array.
Therefore, it is readily apparent that there is a need for an air filter that addresses these problems.